The former Liverpool defender told The Mirror: "Now it is time for the gloves to come off in the Manchester United dressing room. Now is the time for David Moyes to stop mollycoddling the men that are hanging him out to dry and tell them a few home truths.
"Now is the time for Moyes to get the backing from the United hierarchy so that they are singing from the same hymn sheet as they look to deal with their underperforming stars.
"It is time to sit players like Robin van Persie down and tell them straight - 'If you want a new contract you are going to have to perform to a far higher standard than this. Last year was last year. Now we need more from you than you are giving us.'"
United host Olympiacos in the Champions League on Wednesday hoping to turn around a 2-0 deficit from the first leg last month.